Now, a suit filed Tuesday against Dart alleges he “achieved his purpose through false accusations, innuendo, and coercion.”

Backpage hit out particularly at what it considered to be unlawful pressure placed on it by a civil law enforcement entity.

“[W]hereas, if he had brought suit directly or Cook County had attempted to pass a law to shut down the website, Backpage.com would have had a fair opportunity to respond and defeat such efforts, given well-established law,” the complaint continues.

“Sheriff Dart’s actions have not only infringed Backpage.com’s rights to publish and distribute speech, but the rights of millions of the website’s users to post and receive protected speech.”

The site also points to Dart’s previous campaign against fellow classified provider Craigslist, the case against which, involving accusations it encouraged prostitution, was dismissed in 2009. Nonetheless, a year later, Craigslist removed its adult section due to what Backpage calls “quasi-official pressure.”

- Cook County Sheriff Thomas Dart

“Our goal is to ensure that one elected official, particularly a county sheriff, cannot dictate what speech is or is not appropriate,” Liz McDougall, general council to Backpage.com LLC, told the Wall Street Journal.

Backpage has since started offering payments in bitcoin, litecoin and dogecoin for services in its adult section. As the Journal also notes, American Express had similarly withdrawn support for the section, while the Visa and MasterCard ban was extending to its entire catalog.

In a retaliation to the lawsuit and complaint, Dart’s office denounced Backpage’s approach.

“For years, Sheriff Dart has laid out to Backpage the numerous instances where pimps and traffickers have used their site for criminal purposes and attempted to negotiate in good faith with Backpage’s management to find common ground and put traffickers behind bars,” a statement reads.

“It is regrettable that Backpage has dedicated so many resources to lawyers and lobbyists when they could be partnering with law-enforcement to seek justice for sex trafficking victims.”